Marine fouling is a problem within all marine activities such as shipping, within the fish farming industry and within the offshore petroleum industry. Within the shipping industry it is a problem with increased friction which increases the fuel consumption and thereby also increases among other the CO2 emissions. Traditionally toxic ship-bottom paints with zinc and lead compounds which have a harmful effect on organisms in the sea. Within the fish farming industry fouling prohibits flow through of water and thereby also reduces the level of oxygen in the seines. On fixed facilities and on oil facilities fouling can obscure constructional weaknesses and fouling may also accelerate fatigue of facilities such as quays, bridge pedestals and the like.
Pens have traditionally been cleaned by divers which have utilized high pressure water jets for removal of unwanted fouling. Vessels and fixed constructions have also to some extent been cleaned by divers with movable equipment for high pressure washing.
A disadvantage with manual removal is the process is slow, and if a routinely cleaning is requested as it is within the fish farming industry this solution becomes both bothersome and resource-demanding. As a consequence of the shortcomings due to these methods for cleaning more sophisticated and automated equipment for removal of marine fouling have been developed.
An example of a device for cleaning of marine installations is disclosed in Ser. No. 19/986,219 (Andorsen); this device comprises a plate like device with a plurality of rotors which is propelled by high pressure water. The device is guided alongside the objects to be cleaned with supplied high pressure so as to propel the rotors. Under optimal flow conditions this solution works out well.
It is a problem with the “rotor-device” for cleaning of marine installations that under not so optimal flow conditions the “rotor-device” is difficult to maneuver additionally it will often be difficult to follow the surface contour of the body to be cleaned. It shall be noted that the outer walls of the pens—fishing nets—not necessarily hangs straight down so that the fishing nets walls are vertical or follows a parable to its bottom, it is rather common that the pens fishing nets caused by flow conditions follows an s-shape towards its bottom. A number of other installations also have such a shaping that utilization of the rotor-device according to Ser. No. 19/986,219 will not render the requested maneuverability.